The present invention relates to three dimensional digital mapping, and more particularly to devices for controllably directing laser energy upon objects in the course of mapping surface contours of the objects.
Three dimensional laser digitizing is known as an effective technique for collecting information about the surface contours of an object under study Typically a laser beam is directed onto the surface of the object Reflected light is measured to obtain information about the surface contours The information is translated to digital information, from which a wire-frame image of the object can be projected onto a video display terminal. Three dimensional laser digitizing affords substantial advantages over earlier topography measurement schemes involving a contact probe or stylus Laser digitizing involves no contact with the object being measured, and enables surface measurement of soft and fragile objects (e.g. models of clay or flexible foam) without the possibility of damaging the object or distorting the surface Laser systems also afford higher resolution and accuracy, and require no offset calculations.
One of the more challenging aspects in laser digitizing concerns objects with complex, irregular surface topographies. Some point-range laser probes are capable of precision measurement even when the laser beam is substantially offset from perpendicular to the surface under scan. Nonetheless, imaging is enhanced and digital data more reliable, when the laser beam can be positioned approximately perpendicular to such surface. Moreover, it is highly desired to perform scanning automatically and "on the fly", which requires precise rotation and precise translation of the laser probe, to minimize the chance for erroneous topography information due to movement of the laser probe.
Therefore, it is an object of the present invention to provide a means for accurately positioning and translating a laser probe to controllably position and orient a laser beam relative to the surface contours of a scanned object.
Another object of the invention is to provide a means for positioning a laser beam parallel to any vector in a two dimensional space, based on three mutually perpendicular linear translation axes and one rotational axis.
It is a more particular object of the invention to provide a means for positioning a laser beam parallel to any vector in three dimensional space, based on three mutually perpendicular axes of linear translation and two distinct rotational axes.
Yet another object of the present invention is to provide a laser support head adapted for mounting to a precision machining apparatus, with at least one rotational axis and means for precision aligning each rotational axis relative to the machining system.